RU1805130C - Method for control of crude oil dehydration - Google Patents

Abstract

Usage: control of the dehydration process in oil treatment plants, and can also be used in the oil refining industry. The density of water is measured, the interfacial tension of oil and water is determined, the radius of emulsified water droplets, and the flow rate of the chemical is corrected by a mismatch between the current and preset values of the modal radius: 1 silt.

Description

The invention relates to the field of controlling the process of oil dehydration in oil treatment plants and can be used in the oil and refining industries.

The aim of the invention is to reduce the cost of crude oil.

This goal is achieved by the fact that in the known method, which consists in regulating the flow of a chemical agent depending on the temperature and flow rate of NE, the density of emulsified water and the interfacial tension of water and oil are additionally measured, under normal conditions, the measured values are determined the modal radius of the EVC and a correction is introduced for the dosage of the chemical reagent, and with a decrease in the modal radius of the EVC, the dosage of the chemical is increased and vice versa.

Cheese NE arriving at the oil treatment unit is a polydisperse system and has a certain disperse composition (the law of distribution of emulsified water by droplet size). Experimental studies at an industrial plant show that part of NE presented as a finely divided component is such water -drops are small in size and mechanically strong armor shells formed by natural emulsifiers (surfactants) and mechanical impurities and in case of collision are not olescent (do not merge). At the same time, part of such aggregatively stable droplets is carried away from the sump with the oil flow (when the upward flow velocity is greater than the sludge velocity), while the other part, when NE passes through the settling apparatus, accumulate over time on the water cushion and form an intermediate emulsion layer. Due to the fact that the lower part of the intermediate layer adjacent to the water cushion is represented by mechanical impurities and water droplets, protected by a strong armor shell,

With

with

with Oh

ate

with about

preventing interdroplet coalescence in the layer and the transition of the remaining water droplets into solid water, height rm. for which the cost of crude oil for a given value / Sv and stm. is minimal. This proves the correctness of the goal and a significant difference between this method.

The drawing shows a diagram of the implementation of the method.

NE 1 enters mixer 2 through pipeline 1, and x mmr agent enters through pipeline 3 using dosing Naeos 4. The resulting mixture through pipeline 5 through a heater 6 enters the sump (dehydrator) 7. The dehydrated NE with a minimum content of residual water is discharged from the sump through pipeline 8, and the water released from the drain through pipeline 9.

Temperature, NE consumption, water density and interfacial tension of oil and water under normal conditions are measured by sensors 10, 11, 12, 13 and secondary devices 14, 15, 16, 17, respectively. Signals from secondary devices 14, 15, 1.6, 17 enter the computing unit 18, The chemical flow rate is measured by the sensor 19 and the secondary device 20 and is regulated by the controller 21 with the action of the actuator 22 mounted on the bypass line of the metering pump.

Computing unit 14, based on the incoming information, calculates the value of the modal radius of the EVC (rm) and compares it with the nominal and the mismatch signal from the output of the computing unit enters the chemical flow regulator 17 in the form of correction, set point, and the regulator acts on the actuator 18 based on the correction signal .

The modal radius of the EVC is determined by the formula:

where Gt is the radius of the pipeline 1;

V is the flow rate of NE in the pipeline 1;

R is the gas constant;

t is the temperature of the NE;

G is the limiting adsorption of the chemical reagent on the armor shell of the EVC;

dp. One respectively the costs of the chemical and NE;

0

5

0 ° m, Ohm - respectively m, the phase-by-phase tension of water and oil under normal (measured by the device) and operating conditions;

a is the coefficient determined experimentally.

A device that implements the method works as follows. Information on

the values of the parameters t, One, RV, Ohm and measured by the sensors 11 - 13 and secondary devices 14 - 17 are fed to the computing unit 18, where the modal radius of the EEC is calculated by formula (1) - (3) and the settings are changed according to the calculation results chemical flow controller (Qyp) 21, and controller 21 compares this setting with the current chemical value (QTp) measured by the sensor 19 and the secondary device 20, according to the results of the comparison (Qyp QTP), it acts on the actuator 22 and changes the current chemical consumption. Moreover, with Opur - QTP 0, QTP increases, while with Qyp - Q p 0 it is vice versa, and in the case of Qyp - QTP 0 the current flow rate of the chemical does not change.

This method can be implemented in several ways.

Option 1. In the case of the functioning of an automatic process control system for oil treatment, block 14 is not required and algorithms (1) - (4) will be implemented at UVKASUTP.

Option 2. The operator-technologist, receiving information from secondary devices 12 and 13 and the chemical laboratory about the values 0M, pv for known values of G, a, rm, according to the algorithms (1) - (4), can calculate the rm value on an electronic calculator and compare it with nominal value and in case of deviation, change the settings of the chemical flow regulator.

Option 3. It is necessary to develop a computing unit 14 that implements algorithms (1) - (4).

The implementation of the proposed method can prevent the breakdown of the technological regime, reduce losses from substandard conditions, reduce the cost of a chemical reagent, and thereby reduce the cost of salable oil

Claims (1)

The claims A method of controlling an oil dehydration process, including adjusting. the consumption of the chemical depending on the temperature and flow rate of the oil emulsion, characterized in that. in order to reduce the cost of commercial oil, the density of emulsified water is measured, the interfacial tension of water and oil is determined under normal conditions, 5 the radius of the emulsified water is the specified value of the modal radius of the droplets and, according to the mismatch of the current, the chemical consumption is corrected.